c-c bond formation between fischer carbene complex and allylic
TRANSCRIPT
C-C Bond Formation between Fischer Carbene Complex
And Allylic Alcohols promoted by a M(CO)5 Shift
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Literature presentation
Barluenga,J.; Rubio, E.; Lopez, J. A.; Tomas, M. Angew. Chem. Int. Ed. 1999, 38(8), 1091
Universidad de oviedo, Spain
Kamikawa, K.; Uchida, K.; Furusho, M.; Uemura, M. et. Org. Lett. 2004, 6(23), 4307
Osaka Prefecture University, Japan
…Surprisingly, R-allyl â-phenyl propionate 6a was obtained in 75% yield without formation of â-allyl â-phenyl propionate….
---Motokazu Uemura/Osaka Prefecture University
…These lead to unexpected C-H and C-C bond-forming reactions and might be regarded as a further surprise from Fischer carbene complexes….
---Jose Barluenga/Universidad de oviedo
Opportunities in Carbene Chemistry
…Again, the flexibility and/or capriciousness of many transition-metal complexes toward organic substrates becomes more than apparent…
---Jose Barluenga/Universidad de oviedo
[3+3] Carbocyclization through [1,2]M(CO)5 shift
Barluenga, J.; Tomas, M. et. J. Am. Chem. Soc. 1999, 121, 3065
[3+3] Heterocyclization through [1,2]M(CO)5 shift
Barluenga, J.; Tomas, M. et. J. Am. Chem. Soc. 1999, 121, 3065
[4+3] Heterocyclization through [1,3]M(CO)5 shift
Barluenga, J.; Tomas, M. et. J. Am. Chem. Soc. 1999, 121, 3065
Intermolecular Carben Transfer
Sierra, M. A.; Del Amo, J. C.; Mancheno, M. J.; Gomez, M. J. Am. Chem. Soc., 2001, 123, 851-861
Proposed Mechanism for Intermolecular Carben Transfer
Sierra, M. A.; Del Amo, J. C.; Mancheno, M. J.; Gomez, M. J. Am. Chem. Soc., 2001, 123, 851-861
Reaction of CH3ONa/CH3OH with Fischer Carbene complex
Barluenga,J.; Rubio, E.; Lopez, J. A.; Tomas, M. Angew. Chem. Int. Ed. 1999, 38(8), 1091
Reaction of allyl and propargyl alcohol with Fischer Carbene
Reaction of allyl and propargyl alcohol with Fischer Carbene
Proposed mechanism
Support for the Reaction Pathway
Chiral alpha,beta-unsaturated Fischer carbene complex
Vorogushin, A. V.; Wulff, W. D.; Hansen, H.-J. J. Am. Chem. Soc. 2002, 124, 6512-6513.
Barluenga,J.; Rubio, E.; Lopez, J. A.; Tomas, M. Angew. Chem. Int. Ed. 1999, 38(8), 1091
Preparation of binuclear unsaturated Fischer carbene complex
RCHO
(CO)3CrH3C O
M(CO)5CH3+
R
(CO)3Cr
OMe
M(CO5)
Et3N,TMCl/Et2O
Kamikawa, K.; Uchida, K.; Furusho, M.; Uemura, M. et. Org. Lett. 2004, 6(23), 4307
Reactions homobinuclear carbene complexes with allylic alcohols
Reactions heterobinuclear carbene complexes with allylic alcohols
Proposed mechanism
Conclusions
1. Stereoselective [3,3]-sigmatropic rearrangement of chiral binuclear R,â-unsaturated Fischer carbene complexes coulded be promoted by a 1,3-metal shift.
2. Reaction of chiral homobinuclear Fischer carbene complexes with allyl alcohol in the presence of base gave R-allyl esters in up to 97% ee.
3. Hheterobinuclear carbene complexes afforded anti-aldol-type products, R-allyl-â-hydroxy esters, in up to 92/8 dr.